noun
or chalcid wasp
: a usually minute insect of a large superfamily (Chalcidoidea) of Hymenoptera, a few being gall wasps or seed infesters but most being in their larval state parasitic on the eggs, larvae, or pupae of other insects, some living within and others upon the bodies of their hosts, feeding on their juices and tissues, and thus benefiting man by destroying many injurious insects — see clover seed chalcid